Two hours later, Smith who attended college at the University of Missouri in Columbia, addressed the rumors more directly: "Didn't get jumped_ stop asking."

On Thursday morning, Ashley Zavala, a television reporter for the NBC affiliate in Columbia, said on Twitter that Smith was "jumped." A Columbia police spokeswoman confirmed there was a "disturbance" involving two black males at the El Rancho restaurant. Officers were dispatched to the restaurant at 1:56 a.m., but no report was filed.

An El Rancho employee who answered the phone Thursday said she was aware of an incident involving Smith, but declined to provide more details. She said the restaurant's manager was out of town.

A 49ers spokesman said the team had been in contact with Smith. The spokesman said there "is no substance to the rumors that he was jumped." The 49ers are on their bye week, and the players are in the midst of a six-day break. They will report back to the team facility in Santa Clara on Tuesday.

Smith, who turned 23 on Sept. 25, has been involved in a series of off-the-field incidents in 2012, beginning with his arrest on a DUI charge in Miami Beach in late January. In the early hours of June 30, he sustained minor stab wounds at a party at his house outside San Jose. In mid-September he was a passenger in a car that swerved off the road to avoid a deer. The driver of the car suffered a serious back injury, but Smith sustained only a cut above his eye that required stitches.

Smith is tied for fourth in the NFL with 7.5 sacks after collecting two in a 24-3 win against the Cardinals on Monday night. As a rookie in 2011, he ranked fifth in the league with 14, the second-highest total for a first-year player in NFL history.